There is a nitride semiconductor wafer in which a semiconductor layer including a nitride semiconductor (hereinbelow, called a nitride semiconductor layer) is provided on a substrate including silicon. The nitride semiconductor wafer is used to manufacture, for example, a light emitting diode (LED), a high-speed electronic device, a power device, etc. Cracks occur easily in the nitride semiconductor layer of such a nitride semiconductor wafer due to the lattice constant difference and coefficient of thermal expansion difference between the nitride semiconductor layer and the substrate including silicon.